千米深井L型钻孔地面预注浆岩体可注性研究

Study on the Grouting of Rock Mass in Kilometer Deep Well by Surface Ground Pre-grouting of L Type Drilling

以千米深井巷道注浆区域岩体结构分布特征为基础,采用理论分析的方法,结合现有岩体松动压力理论和可注性理论,分析了岩体可注性的影响因素和裂隙岩体渗透的几何参数,利用现场压水试验,统计注浆段地层的单位吸水率,得到吕荣值,对信湖煤矿中央水泵房和变电所注浆加固段岩体的可注性进行评价。分析结果表明,增大岩体的凝聚力和内摩擦角可效降低支护结构承受的松动地压,当岩体的内摩擦角从10°提高到20°时支护结构承受的松动地压降低最显著;所加固段巷道周边岩体的可注性较差,若在巷道开挖施工期采用工作面注浆方法加固围岩,则很难达到预期效果,该研究表明了采用L型钻孔地面预注浆加固围岩的必要性与可行性。

Based on the distribution characteristics of rock mass structure in the grouting area of a kilometer deep mine roadway,using the theoretical analysis method,and the existing rock mass loosening theory and groutability theory,analysis was made of the factors influencing the grouting of rock mass and geometric parameters of seepage in fractured rock masses. The unit water absorption of the grouting section was counted by using the water pressure test in the field to get the Lugeon value with which the groutability of the grouting reinforcement section of the central water pump house and the transformer substation was evaluated of Xinhu coal mine. The analysis results showed that the increase of rock cohesion and internal friction angle could effectively reduce the pressure of supporting structure under a loose rock,when the internal friction angle was enlarged from 10 degrees to 20 degrees,the supporting structure under the loose pressure decreased the most significantly; the groutability of surrounding rock mass of roadway in reinforcement section was poor,it was difficult to achieve the desired effect if the grouting method was used to reinforce the surrounding rock in the construction period of roadway excavation. The research shows the necessity and feasibility of strengthening the surrounding rock with L type borehole surface pre-grouting.